Tool holder and guide



K, W. HOLMBERG TooL HOLDER AND GUIDE Filed March 26, 1955 IN VENTOR.

is passed along the grinder but not in cooperative Patented 24, 1936 PATENT OFFICE TOOL HOLDER GUIDE Weldon Tool Company,

poration of Ohio Karl W. Homberg, cleveland. ohio, assign to Cleveland,I Ohio, a cor- Application March 26, 1935, Serial No. 13,124

3 Claims. (Cl. 51-219) My invention, in general, relates to tool xtures and more particularly to a tool holder and a guide utilized to facilitate the sharpening of tools having one or more spiral cutting edges.

An object of my invention is thefprovision of a fixture or a mechanism for holding andguiding a' tool that is to` be ground'in cooperative grinding relationship with a grinding device such as, for example, a rotary or abrasive grinder.

Another object of my invention is the provision of grinding a tool, which provision comfprises a feeding operation, during which time the tool is passed along the grinder and in cooperative grinding engagement therewith, and a. retrieving operation, during which time the tool grinding relationship therewith.

Another object of my invention is the provision of a guide for aligning a tool having one ,or more spiral cutting edges with a grinder, whereby the cooperative relationship of 'the guide and the spiral edge of the tool to be ground is such that,'

- being ground in perfect alignment with i the grinder.

A still further object of my invention is the provision o f a pivotally mounted tool holder, whereby the tool that is to be ground may be 'brought into cooperative grinding relationship with the grinder during the feeding operation, and whereby the said tool may be tilted away from the grinder when the tool is being returned to its initial feeding position.

A still further object of my invention is the provision of an adjustable guide to accommodate the grinding of tools of different sizes.

'Another object of my invention is the provision of a tool holder and guide which accommodate tools having either left-,hand or right-hand cutting edges. i

A still further object of my invention is the provision of a tool holder which accommodates tools of various sizes. 4 Other objects and -a fuller understanding of my invention may be had by referring to the following description, taken in connection with the accompanying drawing in which:

Figure 1 illustrates a side elevational view of a iixture or mechanism, embodying the features of my invention;

Figure 2' is an end elevational view of my ixture shown in Figure 1, but with parts removed in order, to illustrate more clearly the features of my invention;

Figure 3 is a view taken along the line 3 3, and illustrates the cooperative relationship between the tool and the tool guide, together with 5 the grinder, during the feeding operation;

Figure 4 is a view similar to Figure 3, and illustrates the cooperative relationship between the tool and the tool guide, together with the grinder,

during the time that the tool is being returned' 1o to its initial feeding position; and

Figure 5 illustrates parts of the features shown in Figure 1, wherein tne spindle, which holds the tool that is to be ground, is of a smaller size than that shown in Figure 1, thereby accommodating 15 a range of relatively small tools. v

With reference to the drawing, my invention comprises, in general, a base Il, a pivotally mounted header l5 carried by the base II, a slidable spindle for holding and passing the tool that 20 is to be ground in grinding relationship with the grinder 4I, and a guiding clamp 28 for holding the tool guide 29 in cooperative relationship with the spiral cutting edge of the tool 43.

In accordance with the usual practice, the 25 grinding wheel 44 may be driven by an electric motor (not shown),and carried by a suitable grinding base 45 which may be bolted or otherwise secured to a support 39 which may be a part of an ordinary milling or grinding machine. 30 'I'he base Il which carries the pivotally mounted header I5 and the guide .clamp 28 may be mounted upon a movable support such, for example, as a bedplate I0 of the same milling for grinding machine that supports the grinder M. 35

'I'he base Il may be adjustably bolted to the bedplate I0 by means of the nut and bolt I9. As illustratedthe base Il comprises two upright bearing pedestals I2 and I3 in which is mounted a stationary shaft I4. Each end of the station- 40 ary shaft I4 is provided Withla conical bearing surfaceto receive, respectively, the cone-shaped bearing pins I6 and Il, which pivotally support the header I5 upon the base Il. Accordingly, the header I5 may be tilted or oscillated relative 45 to the base Il, so that in the tilted position, the tool 43 may be actuated away lfrom the grinder 44. As illustrated, the pin bearing Il, is adjustable and may be locked in a xed position, when once adjusted, by means of the lock nut I8.

In order to stabilize the pivotally mounted header I5 upon the base Il, I employ the combination of a spring arrangement and a stop arrangement. As shown in Figure 2, the stop arrangement comprises a stationary screw 56 which 55 is threadably engaged within the header I5 and which is arranged to contact or engage the upper surface of the head of an adjustment screw 55 which threadably engages the base I I.` On the other side of the pivotal connection between the base I I and the header I5, there are positioned two springs 53 and 54 which constrains the staltionary stop 56 to engage the head of the adjustable screw 55. The springs 53 and 54 are held in position by being set in suitable sockets provided therefor. A suitable handle 51 is employed to tilt the header I5 away from the grinder 44. l

'I'he upper main portion of the header I5 is arranged to have the spindle 46 to be slidably and rotatively mounted therein. To this end, the main upper portion of the header I5 is provided with a removable bushing 41 which snugly, but freely, ts within an enlarged longitudinal opening in the header I5, and is securely held in position by means of a set screw 48. In order to attain accuracy in the grinding operation, as well as to afford easy movement of the spindle 46, the outer surface of the spindle and the inner surface of the bushing 41 are very smooth and well matched, such as that produced by lapping the spindle 46 within the inner surface of the bushing 41. Therefore, the operator may grasp the rearward knurled end of the spindle 46 and freely move and rotate the spindle 46 within the bushing 41. As illustrated, the spindle 46 is provided with a longitudinal opening which receives, in its forward end, a removable bushing 50 which, in turn, is adapted to hold the tool 43. Any suitable means may be employed to hold the bushing 50 and the tool 43 within the spindle 46, and to this end, I employ a set screw 5I which threadably engages a threaded opening within the spindle 46 and passes through an enlarged opening 52 in the bushing 56 and engages a fiat portion of the shank of the tool 43. In actual practice, there is provided a tool holder bushing for each different size of tool to be ground. 'Ihis arrangement makes certain that the tool is held firmly within the spindle 46, andprevents any chattering or inaccuracy in the grinding when the tool is fed into cooperative relationship with the grinder 44. While I have illustrated the combination of a tool holder bushing 5l) and a tool 43 having a straight shank, it is to be understood that the combination of the tool holder bushing 50 and the tool 43 may be adapted for tapered shanks as well as for straight shanks.

As shown in Figures 1 and 2, the rearward end of the header I5 is provided with an overhanging portion 20 and the forward end of the header I5 is provided with a similarly constructed overhanging portion 2 I. The lower edge of the overhanging portion 20 is provided with a transverse opening 22, and the lower overhanging portion 2I is similarly provided with a transverse opening 23.

The transverse openings 22 and 23 are adapted to receive the head of the guide support 24. In this manner the guide support 24 may be connected to either end of the header to accommodate tools having both left and right hand spiral cutting edges. In mounting the guide support 24, it is necessary to insert the head 25 within the transverse opening, slide it toits proper transverse position, and then tighten the jam nut 26, which holds the guide support 24 rigidly to the header I5.

As illustrated best in Figures 1 and 3, the guide clamp 28 comprises a block 29 .which slides along the 'guide support 24, and a guide 29 which is adjustably mounted within the block 39 by means of an adjusting nut 3I and a locking nut 32. To accommodate tools of different lengths, the block 39 is arranged to slide longitudinal along the guide support 24, and to insure accuracy in the angular positioning of the guide clamp 2'8, there is provided a longitudinal groove 21 along the guide support 24, so that when adjusting the longitudinal position of the guide clamp 28, it is only necessary for the operator to unloosen the set screw 36, and slide the guide clamp 28 longitudinal along then tighten the set screw 36. In this manner the tightening of the set screw 36 insures accurate angular alignment of the guiding clamp 28 with reference to the guide support 24. The arrangement of the adjusting nut 3| and the locking nut 32 is provided to take care of the vertical adjustment of the guide 29. As shown best in Figure 3, the guide 29 is connected, by any suitable means, to the upper end of a threaded stud 30 which threadably engages the adjusting nut 3|, and the locked nut 32. The lower peripheral shoulder of the adjusting nut 32 is provided with a groove adapted to receive the set screw 35. Also, there is a set screw 34 which threadably enga-ges the block 39 and contacts a lower flattened portion of the shank of the threaded stud 38. The purpose of the set screw 34 is to hold the threaded stud 30 against rotational movement. Therefore, when the set screw 34 is tightened the guide 39 isheld in straight alignment with the underneath side of the flute of the tool being ground. When making vertical adjustments in the guide 29, the operator loosens the screw 35 and turns the adjusting nut 3I to accommodate the elevational position of the guide 29, after which the operator tightens the set screw and turns the locking nut 32 down against the adjusting nut 3|.

In explaining the operation of my tool holder and guide, let it be assumed that the tool 43 is the guide support 24 to its proper position and l properly positioned within the spindle 46 and that the guide 29 is properly set to engage the underneath side of the flute of the tool 43. It is pointed out that the following descriptionof the operation relates to a right-hand tool, such as illustrated, by the tool 43. Starting from the position as shown in Figure 1, which is the end of the feeding operation, the operator rst depresses with his lefthand the handle 51 and tilts the tool 43, as well as the guide 29 from the grinder 44. The tilting position is shown in Figure 4. While in this tilted position, the operator takes his right hand and grasps the rearward end of the spindle 46 and pushes the tool 43 to the left, as shown i'n Figure 1 until the guide 29 rests under the rearward end of the cutting edge that is to be ground. At this point the operator makes certain that the flute which is to be ground rests firmly upon the guide 29. This is done by turning the spindle 46 in a clock-wise direction as viewed from the left in Figure 1, until the flute rmly rests upon` the guide 29. As soon as the rearwardend of the flute to be ground is irmly resting against the guide 29, the operator removes the pressure of his left-hand from the handle 51 and allows the springs 53 and 54 to constrain the header I5 against the stops 56 spindle 48 within the bushing 41 as the operator retracts the spindle to the right as shown in Figure 1. Then after` the ute has .passed along the grinder 44, reaching the position shown in Figure 1, the operator repeats the foregoing cycle until all of the flutes are ground. It is noted from the foregoing cycle of operating that the tool 43 is only brought into grinding engagement with the grinder 44 when the combined action of the ute and the guide 29 is such that the flute always rests upon the guide 29 and turns the spindle 46 within the bushing 41. This is made possible by the tilting action of the header I5, in that the header I5 may be tilted as shown in Figure 4 when the tool is being pushed or returned to its initial feeding position. In the absence of this tilting action, the tool would have to be returned to its initial grinding position while the cutting edge is moved along and in contact with the grinder 44. This would mean that thegrinder 44 would injure the true angle of the cutting. edge, unless the operator would positively rotate the spindle 46 in a clockwise direction, keeping the flute riding on the guide 29 all the time. This is dimcult to do, as the flute, by reason of the spiral, is always tending to leavethe guide 29. The present invention obviates this difliculty; as the tool is returned to its initial feeding position when tilted away from the grinder 44.

In actual practise, the range of the various size of tool to be ground varies from very small tools to very large tools, and for this reason it is difficult to utilize one single spindle for the entire range of tools. This is because the spindle must be big enough to hold the large tools and yet, when this large spindle is attempted to be used to hold a small tool, the constraining force of the guide 29 against the flute is not suilicient to rotate the large spindle. Therefore, in 'this invention I utilize two diiferent sizes of spindles.v The larger size is illustrated in Figure 1 and the smaller size is illustrated by the fragmentary view in Figure 5, wherein the reference character 63 represents the smaller spindle adapted to t within a bushing 62. The arrangement of the bushing 64 for holding the tool 65 is the same as that shown in Figure 1, except smaller. The operation is likewise the same. i

While my invention is particularly adapted to the sharpening of tools having spiral flutes, it is to be pointed out that my invention may be utilized to sharpen tools having straight flutes as well as spiral. 'This is because by my invention, there isno difficulty in aligning the 'tool each time that it is returned to its initial sharpening position.

Although I have described my invention with a to without departing from the spirit and the scope of the invention as hereinafter claimed.

I claim as my invention:

1. In a mechanism for holding and guiding a tool having a longitudinal spiral portion with a longitudinal cutting edge that is adapted to be ground by passing the same longitudinally androtatively along a grinder having a grinding surface of less width than the-longitudinal length of the spiral cutting edge, thus making the spiral cutting edgefthat is ground project beyond the grinding surface of the grinder, in combination,

means for holding the said tool, a header, means for slidably and rotatively mounting the tool holding means in the header, so that the tool may be longitudinally and rotatively passed along the grinding surface of the grinder, thus making the spiral cutting edge that is ground project beyond the .grinding surface of the grinder, a guide adapted to engage the longitudinal spiral portion of the said tool and thus constrain the said longitudinal cutting edge. when the tool is longitudinally passed in the feeding direction s piral tends to leave the guide upon its return movement, may be pivoted away from the grinding surface of the grinder and thereby allow the ground 'spiral cutting edge to be returned to its initial feeding position without being. damaged by contacting the grinding surface of the grinder.

2. In a mechanism for holding and guiding a tool having a longitudinal cutting edge that is adapted to be ground by passing the same longiv tudinally along a grinder having a grinding surface of less width than the longitudinal-length of the cutting edge, thus making the cutting edge that is ground project beyond the grinding sur-l face of the grinder,. in combination, a spindle, means carried by the spindle for holding the said tool, a header having a longitudinal opening adapted to longitudinally receive the spindle, so that the tool may be longitudinally passed along the grinding surface of the grinder, thus mak-` ing the cutting edge that is ground project beyond the grinding surfaceof the grinder, a guide adapted to engage the longitudinal portion of the said tool andl` thus guide the said longitudinal cutting edge in alignment relative to the grinding surface of the grinder, as the tool ist longitudinally pased alongthe grinding surface of the grinder, means for mounting the guide to the header, a base, means for pivotally mounting the its initial feeding position, thereby allowing the ground cutting edge to be returned to its initial feeding position without contacting the grinding surface of the grinder, stop means for aligning the header relative to the grinder each time that the header. is returned to its normal untilted position, and resilient means for constraining the header against the stop means.

3. In a mechanism for holding and guiding a tool having a `longitudinal spiral portion with a longitudinal cutting edge that is adapted to be ground by passing the same longitudinally and rotatively along a grinder having a grinding surface of less width than the longitudinal length of the vspiral cutting edge, thus making the spiral cutting edge that is ground project beyond the grinding surface of the grinder, in combination,

ing the said tool, a header having a longitudinal opening, a bushing adapted to fit into the longitudinal opening of the header, said bushing having an `opening-adapted to receive the spindle, whereby the spindle may be longitudinally and rotatively moved within the bushing, aguide supi a spindle, means carried by the spindle for holdport adjustably mounted upon the header and arranged to extend therefrom in spaced relationship with the tool, a guide, means for adjustabiy mounting the guide upon the guide support, said guide being adapted to engage the spiral portion of the said tool and thus constrain the said cutting edge, when the tool is longitudinally passed in the feeding direction along the grinding surface of the grinder, to ride upon the guide and thereby rotate and align itself relative to the grinding surface of the grinder, a base, means for pivotally mounting the header tothe base, so that the spiral portion of the tool, which has been rotated by the guide relative to the grinding surface of the grinder during the feeding movement and which by reason of the spiral tends to leave the guide upon its returnmovement, may be pivoted away from the grinding surface of the grinder and thereby allow the ground spiral cutting edge to be returned to its initial feeding position without being damaged by contacting the grinding surface of the grinder, stop means for aligning the header relative to the grinder each time that the header is returned to its normal untilted position, and resilient means for constraining the header against the stop means.

KARL W. HOIMBERG. 

